If you wish to have complete control over a blog, the ability to upload themes and plugins, and to edit themes and templates then your option is to hire a web host and get a free software install from WordPress.ORG and self host it.http://en.support.wordpress.com/com-vs-org/

sorry if i am bothering you but those links you gave me wasn't helpful
i cannot find a way to upload csv file or to add books manually one by one and also
I can 't find how to upload images of book covers

@liridonk, that isn't going to be possible at wordpress.com. Although wordpress.com has no problem with you selling things that you actually make or create (your art, a book you write, jewelery, etc.) they do not allow full ecommerce and the selling of stuff you buy.

You need to get yourself your own domain name, hire a web hosting company and install the software from wordpress.ORG and then find and install a shopping cart module. Figure about $25 to as much as $50 per month, all costs considered, for a complete ecommerce setup with SSL and everything.